A Modified Vector Control Strategy for DFIG Based Wind Turbines to Ride-Through Voltage Dips

Nowadays, the wind market is dominated by doubly fed induction generator (DFIG) based wind turbines. However, they are very sensitive to grid faults due to the small rated power converters and direct connection to the grid. In order to improve its Low Voltage Ride-Through (LVRT) capability, this paper proposes a modified vector control strategy of the DFIG by considering the dynamics of stator flux deduced by grid voltage dip. The limitation of the proposed scheme is also presented with a feasible region, which indicates the necessity of additional protection implementation such as crowbar. Then coordinated control strategies are proposed to enhance the LVRT performance with grid voltage support capability. Simulation results show the effectiveness of the proposed control schemes.